The Boeing Company

Alan C Kernik

Wilfred E Boehringer

Colin P Gatehouse

Neal F Gilleran

A brake squeal attenuator for use with aircraft wheel brake assemblies. The attenuator includes a housing having a piston member and a weight disposed therein. The piston member and weight are biased by a spring disposed within the housing. The housing includes a neck portion which is in fluid communication with the hydraulic actuators of the brake assembly with which the attenuator is being used. The piston thus is biased on one side thereof by the biasing member and on an opposite side thereof by the hydraulic fluid pressure acting thereon. During braking, when torsional oscillations occur in the brake assembly which would otherwise cause objectionable brake squeal to occur, the entire housing of the attenuator, which is fixed to the housing of the wheel brake assembly, moves in accordance with the torsional oscillations which occur. The weight associated with the piston member causes movement of the piston member to lag behind movement of the attenuator housing as the attenuator begins oscillating. The attenuator thus produces a pumping of hydraulic fluid to and from the hydraulic actuators of the brake assembly which are timed to damp the torsional oscillating movement of the wheel assembly. The attenuator can be easily retrofitted to virtually all aircraft wheel brake systems without significantly adding to the cost or complexity of such systems.

Brake squeal attenuator apparatus and method

A computer-controlled shock strut for a vehicle suspension system includes an infinitely adjustable damping valve connecting two internal fluid-filled chambers within the strut, such that compression and extension of the strut piston causes fluid to pass between the chambers through the damping valve. A microprocessor-based controller continuously and actively controls the position of the damping valve in response to input signals from various sensors associated with the strut, with the vehicle, and/or with the suspension system, so as to vary the damping rate of the strut to control piston position and motion. The strut also includes fluid supply and return valves which couple the two chambers to a pressurized fluid supply and a fluid return, respectively, to permit fluid to be added to or discharged from the strut. The supply and return valves are also controlled by the controller so that strut length can be controlled.

Growing community of inventors

Long Beach, CA, United States of America

Alan C Kernik